Physics - Condensed Matter Seminar

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Condensed Matter Seminar: "Spin waves in chiral two-dimensional electron systems"

Event Type
Physics - Condensed Matter
ESB 190
Oct 13, 2017   1:00 pm  
Carsten Ullrich, University of Missouri

In this talk I will discuss our recent theoretical and experimental results for spin-wave dispersions in n-doped semiconductor quantum wells subject to in-plane magnetic fields. Our particular focus is on the interplay between spin-orbit coupling and electronic many-body effects. Rashba and Dresselhaus spin-orbit coupling induces a wavevector-dependent spin splitting in the conduction bands. The spin waves hence travel through a spin-orbit twisted medium, which leads to interesting new ways of controlling the direction and group velocity of the spin waves. Due to the absence of spin-rotation invariance, Larmor's theorem is broken. For the special case of equal-strength Rashba and Dresselhaus spin-orbit coupling, a new exact many-body result is found, which we call the spin helix Larmor mode.

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